The Clean Power Plan established state goals and energy source requirements to reduce power plant pollution. Eliminating these rules eases the burden on power plants in coal-reliant states like Kentucky, which is one of the upwind states in Maryland’s lawsuit, along with Indiana, Ohio, Pennsylvania, and West Virginia.

Although the EPA’s repeal presents a challenge for Maryland’s lawsuit, it’s unlikely to change the state’s own plan to cut greenhouse gas emissions by 40 percent by 2030. The Maryland Healthy Air Act, which received bipartisan approval, sets tighter limits on coal plants than the federal plan did. Maryland is also part of the Regional Greenhouse Gas Initiative, which auctions power plant emission allowances across the Northeast.

In the meantime, the Clean Power Plan repeal proposal will undergo a public-comment period, and a replacement regulation will be considered, which will also seek public input. There is no firm timeline on how long all of it will take.